The molecular basis for scent discrimination: Response to nitrobenzene-d5 of honey bees (Apis mellifera L.) conditioned with nitrobenzene

Zusammenfassung Honigbienen,Apis mellifera L., wurden dressiert, Zuckersirup an Stellen zu sammeln die mit Nitrobenzol markiert waren. Wenn Nitrobenzol oder Nitrobenzol-d ₅ zur Auswahl standen, konnten die Bienen nicht zwischen diesen Analogen unterscheiden. Dieses Ergebnis stimmt mit der Überlegung überein, dass die Chemorezeptormechanismen mit Elektronenmustern odereffekten zusammenhängen und nicht auf Oszillations-und Rotationsfrequenz, Dipolmoment oder anderen Masseneffekten an Molekülen beruhen.

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Acknowledgment: Dr.R. L. Feltham, Chemistry Dept., andK. R. Armstrong, Lunar and Planetary Lab., University of Arizona, obtained the far-IR-spectra.Othon Ziehl assisted in bioassays.     

The evolution of a trading zone: a case study of the turtle excluder device

This paper explores the evolution of a trading zone by organizing the case study of turtle excluder devices within the model proposed by Collins et al. (2007). The case study offers evidence that trading zones do evolve and that the concepts of enforced and fractionated trading zones hold practical utility for describing and defining the complexities of actual exchanges. In this case a trading zone evolved from enforced to fractionated and ultimately diverged into two trading zones. For each step of the evolution I describe the forces that drove these transitions. Finally, I present an adapted trading zone model that is conceptually a better fit for the turtle excluder device case study.     

Stimulation of methemoglobin reduction by selenium: a comparative study with erythrocytes of various animals

The extent of stimulation of methemoglobin (metHb) reduction by selenite depends upon the level of reduced glutathione (GSH) in the erythrocytes. The reason for the species difference in the effect of selenite was discussed with respect to species differences in the GSH levels in erythrocytes.     

The membrane component of the ribosomal bodies from the lizardLacerta sicula: a freeze-etching study

Summary We have studied, using the freeze-etching technique, the cytomembranes of the flat cystenae, regularly interposed between the cristalline sheets of ribosomes, inside the ribosomal bodies of the hibernating lizardLacerta sicula. The results show the presence, on the protoplasmic face (PF), of numerous IMPs (intramembrane particles) which can be separated into two populations. The flatter ones appear to be arranged in a regular pattern, with the support of the optical diffraction analysis, can be correlated with the disposition of the ribosomes in the cristalline sheets.6 October 1986     

The flow of a solution into a tube filled with solvent: Mathematical derivations

Résumé On offre un ensemble d'équations qui s'appliquent à l'écoulement laminaire de deux solutions A et B, de même viscosité, lorsqu'on introduit B dans un tube préalablement rempli de solution A.     

The evolution of sales forecasting management: a 20‐year longitudinal study of forecasting practices

This paper presents results of a survey designed to discover how sales forecasting management practices have changed over the past 20 years as compared to findings reported by Mentzer and Cox (1984) and Mentzer and Kahn (1995). An up‐to‐date overview of empirical studies on forecasting practice is also presented. A web‐based survey of forecasting executives was employed to explore trends in forecasting management, familiarity, satisfaction, usage, and accuracy among companies in a variety of industries. Results revealed decreased familiarity with forecasting techniques, and decreased levels of forecast accuracy. Implications for managers and suggestions for future research are presented. Copyright © 2006 John Wiley & Sons, Ltd.     

The human leukemia cell line, THP-1: a multifacetted model for the study of monocyte-macrophage differentiation

THP-1 is a human monocytic leukemia cell line. After treatment with phorbol esters, THP-1 cells differentiate into macrophage-like cells which mimic native monocyte-derived macrophages in several respects. Compared to other human myeloid cell lines, such as HL-60, U937, KG-1, or HEL cell lines, differentiated THP-1 cells behave more like native monocyte-derived macrophages. Because of these characteristics, the THP-1 cell line provides a valuable model for studying the mechanisms involved in macrophage differentiation, and for exploring the regulation of macrophage-specific genes as they relate to physiological functions displayed by these cells.     

The effect of continuous exposure to low frequency electric fields on three generations of mice: a pilot study.

Mice were allowed to mate, gestate, deliver and rear their offspring for 3 successive generations while being continuously exposed to 60 Hz electric fields. Mice exposed to vertical electric fields exhibited decreased body weights at 35 days postpartum and increased mortality rates for 3 successive generations. Mice exposed to horizontal electric fields exhibited decreased body weights for 2 successive generations.     

Forecasting nonlinear time series with feed‐forward neural networks: a case study of Canadian lynx data

The forecasting capabilities of feed‐forward neural network (FFNN) models are compared to those of other competing time series models by carrying out forecasting experiments. As demonstrated by the detailed forecasting results for the Canadian lynx data set, FFNN models perform very well, especially when the series contains nonlinear and non‐Gaussian characteristics. To compare the forecasting accuracy of a FFNN model with an alternative model, Pitman's test is employed to ascertain if one model forecasts significantly better than another when generating one‐step‐ahead forecasts. Moreover, the residual‐fit spread plot is utilized in a novel fashion in this paper to compare visually out‐of‐sample forecasts of two alternative forecasting models. Finally, forecasting findings on the lynx data are used to explain under what conditions one would expect FFNN models to furnish reliable and accurate forecasts. Copyright © 2005 John Wiley & Sons, Ltd.     

Interaction of Co, Mn, Mg and Al with d(GCCCATGGC) and d(CCGGGCCCGG): a spectroscopic study

Spectroscopic study of the interactions of metal ions, Co, Mn, Mg and Al with d(GCCCATGGGC) and d(CCGGGCCCGG) revealed the following. Metal ions Mn, Al and Mg at the lowest concentrations enhanced the t _m of oligomers, whereas Mn and Mg at higher concentrations decreased the t _m . Co enhanced the t _m of oligomers at higher concentrations. The studies have also indicated that Mn at lower concentrations displaced EtBr fluorescence, Mg and Co at moderate concentrations and Al only at higher concentrations. Addition of Co, Mn, Mg and Al altered the bands of the circulars dichroism (CD) spectra of the oligomers in a concentration-dependent manner. The CD spectra of d(GCCCATGGGC) and d(CCGGGCCCGG) indicated B and Z forms of DNA, respectively, in contrast to the A form observed in the crystal structures. Mg and Co at different ionic strength induced Z–B transition in d(CCGGGCCCGG), while Al at higher concentrations induced a Z–A transition. Mn did not induce any transition. This is the first report to show that Al causes structural transitions in sequence-specific oligomers and has strong binding ability with GC-rich euchromatin oligomers. Received 22 December 1997; received after revision 16 March 1998; accepted 16 March 1998     

The mensuration of quadrilaterals and the generation of Pythagorean triads: A mathematical,heuristical and historical study with special reference to Brahmagupta's rules

Summary The ancient rule for the area of a quadrilateral, , is examined to show its inaccuracy and its arbitrariness, and in order to see how those using it might have become aware of its shortcomings. Consideration ofBrahmagupta's vastly more sophisticated rule, , and of the Hindu schedule of recognized quadrilateral types, leads to the question of the proper assessment to be made of this strand of Indian mathematics. The work on quadrilaterals was intimately connected with the generation of Pythagorean triangles out ofbja (=seed) numbers by the same method as had probably been used by the mathematicians of Old Babylonia. Ways in which this procedure could have arisen by induction from particular numerical calculation are shown and the rest of the study consists primarily of an investigation as to whether the same kind of approach might not also have been used to obtain the remarkable rules on quadrilaterals given byBrahmagupta. It is found that there is no compelling need to adopt the common assumption thatBrahmagupta must have had access to Alexandrian mathematics. But even if he did chance to learn of some helpful items from the works ofHero orPtolemy, it still seems necessary for a proper appreciation of his understanding of the mensuration of quadrilaterals to suppose that he would have worked such items into the contemporary Indian mathematical context in some such way as is indicated here. In particular, it is argued thatBrahmagupta, far from indulging in reckless generalization, could well have proceeded with great caution, from one amenable type of quadrilateral to another, verifying his inductions by comparing them with results given by alternative calculation methods.     

Action and teleaction of specific ligands on DNA: a quantitative study with Azbel's model and an application to the regulatory mechanism of the lac operon]

Assuming that the action of specific ligands is transferred to DNA via the bases in close contact with the ligand, which are stabilized (or destablized) in this process, the local and more distant action of the ligand on DNA can be evaluated quantitatively with the aid of Azbel's model. An application to the system regulating the E. coli lac operon is presented.     

The effects of chronic alcohol ingestion in mice on contractile properties of cardiac and skeletal muscle: a comparison with normal and dehydrated-malnourished controls.

In vitro isometric contractile tension was measured in heart and skeletal muscle in 3 groups of mice: 1. a control group, 2. a group maintained for 27 weeks on 20% alcohol, and 3. a group whose fluid intake was restricted to the extent equaling that which occurred in the alcohol treated animals. Results showed a reduction in cardiac twitch tension in both the alcohol and fluid restricted group, as compared to normal controls. We therefore consider that dehydration per se may play an important role in the etiology of alcoholic cardiomyopathy.